Floor covering for radiant heating installations



June 5, 1962 w. 1. WILLIAMS 3,037,745

FLOOR COVERING FOR RADIANT HEATING INSTALLATIONS Filed Nov. 10, 1958 /A/V'N 70R WESLEY 1'. VV/LL/A M5 8 Y HIS A TTORNE'KS H4 22/5, ff/scw, E5752. 5 Mae/215 Unite States This invention relates to radiant heating systems and to tiles for installation against a fiat surface such as a floor, wall, ceiling, etc. for covering a heating element overlying such surface.

Radiant heating systems have not been widely accepted for heating rooms, ofiice areas, etc. for various reasons. Among these reasons are the excessive cost of the initial installation and the difiiculty of repairing stoppages, leaks, etc. in the heating conduit of the system. The present invention seeks to overcome these disadvantages in prior radiant heating systems. It can be installed with almost equal ease in new or existing structures. One of the important objects of the invention is to provide a radiant heating system which is economically constructed and capable of being rapidly and conveniently installed at low cost in existing structures. A further object is to provide a unique tile which can be installed in numbers suflicient to cover a surface and an overlying sinuous heating element.

Another object is to provide such a tile that is grooved on its under side to receive portions of the heating element, the exposed side of the tile presenting a durable and attractive appearance to the room.

A further object is to provide a radiant heating system characterized by low maintenance and repair costs and in which rapid and convenient access can be had to the heating element should servicing be required.

These and other objects of the invention can be attained by positioning an elongated heating element on the surface in a sinuous pattern and covering it with relatively large tiles, preferably molded of plastic material, these tiles being grooved to receive sections of the sinuous heating element. One of the important features of the invention is to provide a tile which is so grooved that it can be used to cover both straight runs and curved end sections of a sinuous heating element.

A more detailed description of a specific embodiment of the invention is given below with reference to the accompanying drawing in which:

FIG. 1 is a fragmentary isometric view showing an assembly of the radiant heating system of the invention on the floor of a room;

FIG. 2 is a vertical sectional view taken along the line 22 of FIG. 1; and

FIG. 3 is a perspective view of the under surface of a tile of the invention showing the preferred arrangement of the grooves therein.

FIG. 1 suggests a floor extending from wall to wall of a room. It may be an existing floor and may be made of wood or any other flooring material such as concrete, asphalt, metal, etc. A layer of heat insulating material 11 is usually placed on the surface of the floor to reduce the transmission of heat into the floor and to areas therebeneath. It may or may not be needed to protect the floor from the heating element. The insulating material 11 may be in sheet form and can be laid in block, strip or tile form to cover the floor surface. In some instances, the heat insulating material can be applied in fluid or plastic state, being spread over the surface and allowed to dry or set. In some instances, the heat insulating material 11 can be a heat reflective material such as aluminum foil, polished metal, etc. Both reflective and low heat conductivity coatings can be applied if desired.

The heating element 12 can take any one of a number of forms but preferably is of the circulating fluid type ate I 3,637,746 Patented June 5, 1962 including a conduit laid sinuously on the surface. In the preferred practice of the invention, the conduit is formed of a series of straight or parallel runs 13 with their ends appropriately connected by end sections 14. The latter are preferably semicircular in shape. In the preferred practice of the invention the heating element is made of copper tubing. The ends of the semicircular end sections 14 are swaged or enlarged to receive and be soldered to the ends of straight lengths of tubing forming the parallel runs 13. The swaged ends of the end sections 14 are indicated by the numeral 15 in FIG. 1. The arrangement is such that the tubing can be laid in a regular sinuous pattern by use of standard parts, including the end sections 14 and the straight runs 13. The latter are cut to predetermined lengths sufficient to traverse the room to be heated. With very large areas, the sinuous pattern can be repeated in the different areas of the floor. The inlet and outlet ends of the sinuous conduit are connected to a suitable hot water heater, the water being circulated thermally or by a pump, the temperature being preferably thermostatically controlled in a known manner.

The invention contemplates that the sinuous heating element '12 shall be covered by a plurality of identical tiles '16, each providing a smooth upper surface 17 and a grooved under surface 18. These tiles are preferably molded from suitable plastic material which may be either homogeneous or strengthened by fabrics, fibers, etc. A desirable plastic material is a mixture of a suitable resin and wood fibers, the latter being known variously as wood flour, Wood pulp, ground wood, etc. The upper surface of each tile is provided with an attractive finish. Desirably, this upper surface is a molded surface. It may itself form the ultimate floor surface or it may be covered with suitable floor coverings if desired.

The under surface 18 is formed With a pattern of grooves during the molding operation, this pattern being best shown in FIG. 3. Referring thereto, the preferred pattern includes two or more longitudinal grooves 19 traversing the tile from end to end and spaced from each other a distance equal to the spacing of the parallel runs 13. The tiles are preferably rectangular, being of a width approximately twice the spacing of the straight runs 13 whereby the grooves 19 are respectively approximately one-fourth the tile width from the side thereof and about one-half the tile width from each other.

To accommodate the end sections 14, where these, occur, each tile includes a substantially semicircular groove 20 bridging the longitudinal grooves 19. It has the same curvature as the end sections 14 and is preferably of a radius of about one-fourth the tile Width in the preferred form. In instances where the end sections 14 are not semicircular, the groove 20 will be of conforming shape. A tile grooved as thus far defined can be used to cover all intermediate sections of the heating element 12 and those terminal portions thereof Where the end sections 14 are centered beneath a tile, as is the case with the tile 16a suggested in FIG. 1.

To accommodate the opposite terminal portion, as where the end section 14a loops from one row of the tiles to the next, it is desirable to provide each tile with two lateral grooves 21 each substantially quarter circular and each having a radius of about one-fourth the tile width to correspond to the radius of the semicircular groove 20. The inner end of each lateral groove 21 opens on one of the longitudinal grooves 19 at the point where this groove meets the semicircular groove 20'. The other end of each lateral groove 21 opens on a side of the tile 16. correspondingly, when two of the tiles 16 are disposed side by side, the joining lateral grooves 21 thereof compositely form a semicircular groove similar in shape and dimension to the semicircular groove 20 and adapted to receive and cover one of the end sections 14a.

The longitudinal grooves 19 are preferably of a width only slightly larger than the width of the heating element 12 and of a depth only slightly greater than the height thereof. However, the semicircular groove 20 and the lateral grooves 21 are preferably of much greater width. As the straight runs 13 of the heating element expand and contract, the wider grooves 20 and 21 accommodate the shifting of the end sections 14 so that undue stress is not placed on any portion of the system due to changes in temperature.

With tiles that can be interchanged end for end, such an arrangement of grooves is sulficient to cover all portions of the heating element 12. However, if the tiles are of a design requiring that all be disposed in a given endto-end relationship, it is desirable to design each tile with a supplementary semicircular groove 20a and two supplementary lateral grooves 21a at the opposite end of the tile from the grooves 20 and 21, all as best shown in FIG. 3. The grooves 20a and 21a are concave toward the center of the tile, as are the grooves 20 and 21.

It is preferable that the end edges and side edges of adjacent tiles should intermesh in locking relationship. Conventional tongue-and-groove means can be employed but I prefer to utilize interlocking means best shown in FIGS. 2 and 3. In this connection, one side of each tile provides a flange 22 protruding sidewise in the upper half of the tile. The opposite side of the tile provides a flange 23 protruding from the lower half of the tile. The flange 23 of one tile extends beneath and interlocks with the flange 22 of an adjacent tile. In the same way, a flange 24 extends from one end of the tile in the same plane and of the same thickness as the flange 22. At the opposite end of the tile a flange 25 extends in the same plane as the flange 23. This flange 25 thus fits beneath the flange 24 of an adjacent tile to interlock the ends of the tile.

Alternatively or in addition, each tile may provide four or more holes 27 near the respective concerns or at other suitable locations, these being preferably counter-sunk to receive flat-headed screws 28 which are driven into the floor through the heat insulating layer 11. It is desirable that each of the screw heads be countersunk a sufiicient distance to receive a circular plug 29 which is glued in place flush with the top surface 17 of the tile.

The tiles 16 can be made in molds by suitable techniques known in the art of molding plastics and plastic compositions. Attractive surfaces can be produced by impregnating clear or colored plastics with wood chips, shavings, sawdust, or wood fibers. The resulting tiles will have an attractive finish and will not require floor coverings.

It will be seen that the heating element 12 can be conveniently assembled on an existing floor, the end sections 14 being soldered to straight runs 13 previously cut to the desired length. The resulting sinuous conduit need not be attached to the floor. Starting at one corner of the room or area, the tiles 16 may be laid progressively. If necessary, the conduit is displaced slightly so that its various portions will fit into the grooves of the tiles as they are progressively laid. In this respect, the tiles insure accurate shaping of the heating element, If it is desired later to secure access to any portion of the heating element, it is not necessary to wreck the tiles. They can be locally removed in the area to be inspected and can be relaid in the original pattern.

Tiles of rectangular shape and of a size in the neighborhood of 2 feet by 4 feet are preferred, employing the complete pattern suggested in FIG. 3. However, it is within the scope of the invention to employ smaller tiles. For example, tiles shaped to correspond to halves or quarters of the tile of FIG. 3 can be employed. In these instances, the tile may include a single longitudinal groove 19 traversing the tile from end to end with two lateral grooves flaring therefrom, these lateral groove corresponding to the lateral groove 21 and one half of the semicircular groove 20 previously described.

Although I have shown and described a preferred embodiment of the invention, I do not intend to be limited thereto but wish to be afforded the full scope of the following claims.

I claim as my invention:

1. A radiant heating tile adapted to be assembled with identical tiles to cover an elongated heating element overlying a surface in a sinuous pattern including parallel runs connected by end sections, said tile comprising a fiat four-sided body having a smooth exposed surface and an under surface grooved to receive said heating element when placed thereover, the groove in said under surface including at least one longitudinal groove traversing said tile from end to end to receive one of said parallel runs of said heating element, and two lateral grooves curved sidewardly in opposite directions from such longitudinal groove at a point intermediate the ends thereof to receive at least one-half of one of said end sections of said heating element, at least one of said lateral grooves extending to a side of said tile.

2. A tile as defined in claim 1 in which said grooves are of a depth slightly greater than the height of said heating element, the width of said longitudinal groove being slightly greater than the width of said heating element, the width of each of said lateral grooves being substantialiy greater than the width of said longitudinal groove, thereby accommodating shifting of said end section of said heating element as said parallel runs expand.

3. A tile as defined in claim 2 in which said tile is molded and in which said grooves are molded therein, said smooth exposed surface being a molded surface, an adjacent side and end of said tile having flanges overlying edge portions of adjacent tiles, the other side and end of said tile providing flanges fitting beneath corresponding edge portions of tiles adjacent thereto.

4. A radiant heating tile adapted to be assembled with identical tiles to cover an elongated heating element overlying a surface in a sinuous pattern including parallel runs connected by end sections, said tile comprising a rectangular body having a smooth exposed surface and an under surface grooved to receive said heating element when placed thereover, the grooves in said under side including two parallel longitudinal grooves traversing said tile from end to end and spaced from each other a distance equal to the spacing of said parallel runs of said heating element, and a pair of lateral grooves curving sidewardly in opposite directions from each longitudinal groove at corresponding points between the ends of the respective longitudinal grooves, one lateral groove of each pair extending to the side of the tile, the other lateral groove of the pairs of lateral grooves meeting and forming a lateral passage corresponding in shape to one of said end sections of said heating element.

5. A radiant heating tile adapted to be assembled with identical tiles to cover an elongated heating element overlying a surface in a sinuous pattern including parallel runs connected by end sections, said end sections being substantially semicircular, said tile comprising a rectangular body having a smooth exposed surface and an under surface grooved to receive said heating element when placed thereover, the grooves in said under side including two parallel longitudinal grooves traversing said tile from end to end and spaced from each other a distance equal to the spacing of said parallel runs of said heating element, said longitudinal grooves being about onefourth the tile width from the sides thereof and being spaced about one-half the tile width from each other, a substantially semicircular groove bridging said longitudinal grooves and having a radius about one-fourth the tile width, and two lateral grooves each substantially quarter circular and each having a radius of about onefourth the tile width, each of said lateral grooves opening at one end on one of said longitudinal grooves adjacent the junction of such longitudinal groove and one end of said semicircular groove, each of said lateral grooves opening at its other end on a side of said tile.

6. A radiant heating tile adapted to be assembled with identical tiles to cover an elongated heating element overlying a surface in a sinuous pattern including parallel runs connected by end sections, said end sections being substantially semicircular, said tile comprising a rectangular body having a smooth exposed surface and an under surface grooved to receive said heating element when placed thereover, the grooves in said under side including two parallel longitudinal grooves traversing said tile from end to end and spaced from each other a distance equal to the spacing of said parallel runs of said heating element, said longitudinal grooves being about one-fourth the tile width from the sides thereof and being spaced about one-half the tile width from each other, two semicircular grooves bridging said longitudinal grooves and positioned respectively near the ends of the tile and re spectively convex toward said ends, and four lateral grooves each substantially quarter circular with a radius about one-fourth the width, each of said lateral grooves opening at one end on one of said longitudinal grooves adjacent the junction of said longitudinal groove and one end of a semicircular groove, each of such lateral grooves opening at its other end on a side of said tile.

7. A radiant heating system for installation on an existing floor surface, comprising: a continuous pipe overlying said floor surface in a sinuous pattern, said pipe including parallel runs of straight pipe joined in a sinuous pattern by substantially semicircular end sections, said pipe having inlet and exit ends adapted to receive and discharge a heating fluid; and a plurality of individual molded tiles fitted edge to edge in a pattern that compositely covers said surface and the pipe, said tiles having smooth surfaces exposed to the interior of the room and grooved under surfaces, each tile including two straight parallel grooves freely receiving two of said runs of straight pipe, at least the end tiles of said tile pattern each having a semicircular groove inward of the end of such tile joining intermediate portions of the straight grooves thereof and a branch groove extending from such intermediate portion of at least one of such straight grooves to a side of such tile, said semicircular groove and said branch groove corresponding in curvature to the semicircular end sections of said pipe and freely receiving same.

8. A radiant heating system for installation over an existing floor surface, comprising: a pipe overlying said floor surface and laid loosely thereon in a sinuous pattern, said pipe including spaced-apart runs of straight pipe sections free of joints and separate curved end sections of pipe of substantially semicircular form joining the ends of said straight pipe sections, said pipe having inlet and outlet ends for receiving and discharging a heating fluid; and a plurality of molded tiles fitted edge-toedge in a pattern compositely covering said surface and said pipe, each of said tiles having grooved undersurfaces receiving said pipe and including two straight parallel longitudinal grooves respectively receiving two of said spaced-apart runs of straight pipe and of a width greater than the diameter of such runs, at least the end tiles of the tile pattern having a semicircular groove joining said longitudinal grooves and disposed inward of the end of such tile, said semicircular grooves being of a width substantially greater than the width of said longitudinal grooves to receive said curved end sections of pipe and provide for movement thereof relative to said floor surface caused by changes in temperature.

9. A radiant heating system for installation over an existing floor surface, comprising: a continuous pipe overlying said floor surface in a sinuous pattern and ineluding parallel runs of straight pipe free of joints and separate curved end sections of pipe of substantially semicircular form joining the ends of said runs of straight pipe, said continuous pipe having inlet and exit ends for receiving and discharging a heating fluid, the end sections being free of attachment to said surface so as to move relative thereto with expansion and contraction caused by a change in temperature of said heating fluid; and a plurality of molded tiles fitted edge-to-edge in a pattern compositely covering said surface and said pipe, said tiles having smooth top surfaces composi-tely forming a flat floor surface, each of said tiles having a grooved undersurface providing two straight parallel longitudinal grooves respectively receiving two of said parallel runs of straight pipe and of a width greater than the diameter of such straight runs, at least the end tiles of the tile pattern having a semicircular groove disposed inward of the end of such tile interconnecting intermediate portions of said straight grooves, such end tiles having a branch groove extending from such intermediate portion of a straight groove to and opening on a side of such tile, each such semicircular groove and its branch groove being of a width substantially greater than the width of said longitudinal grooves to receive said semicircular end sections of said pipe and provide for the aforementioned movement thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,359,400 Lightfoot Nov. 16, 1920 1,771,269 Musgrave et al. July 22, 1930 1,800,150 Musgrave et al. Apr. 7, 1931 2,138,217 Sutter Nov. 219, 1938 2,559,198 Ogden July 3, 1951 2,878,530 Lindstrom Mar. 24, 1959 FOREIGN PATENTS H21,583 Germany Dec. 13, 1956 

